TGO cassis flight model

CaSSIS is a colour imager that will obtain high-resolution images of the Martian surface. The telescope's aperture is around 13.5 cm in diameter, and the 4 mirrors comprising the telescope are held in a carbon-fibre reinforced polymer (CFRP) structure. The focal plane consists of a single silicon hybrid detector with 4 colour filters mounted on it.

Both the telescope and focal plane are mounted on a rotation mechanism. This allows us to solve two key problems. Firstly, the rotation of the spacecraft about the nadir direction can be compensated for, and secondly, the rotation mechanism can be swivelled by 180 degrees to acquire an almost instantaneous stereo image of a target.